Anyone with an 88 325is with M5X swap?

[bwh13]

Trying to determine if my 3/88 build date car is the same as others built in this model year.

I traced the Instrument cluster circuit board from pin 12 with the brn/red wire from the speed sensor to the speedometer. Output from pin 10, which connects to the C101 pin 14, sending the speed sensor signal to the DME. I couldn't find the connection from pin 12 to pin 10 on the circuit board.

I traced the blu/yel wire from pin 10 in the white plug to the C101 pin 14 so that has a clear path to the engine harness and on to the DME.

However, when testing the circuit board for continuity between pin 12 (input from speed sensor) to pin 10 (output to DME) I came up with nothing.

How does the speed sensor signal get from pin 12 to pin 10, then on to the C101 pin 14?

[e30polak]

If your car was an auto, then you need to hook up a wire to the cluster as well. My car had this problem, but it's a '90.

[bwh13]

Mine is a manual trans. I did run a wire from the bottom of the speedo where the cruise control blu/yel wire plugs into it to the blu/yel going to the C101 to tap the speed sensor signal. We'll see if the CEL for the speed sensor comes on today...